Solve for $x$ and $y$ using substitution. ${-2x+3y = -9}$ ${y = -3x+8}$
Answer: Since $y$ has already been solved for, substitute $-3x+8$ for $y$ in the first equation. ${-2x + 3}{(-3x+8)}{= -9}$ Simplify and solve for $x$ $-2x-9x + 24 = -9$ $-11x+24 = -9$ $-11x+24{-24} = -9{-24}$ $-11x = -33$ $\dfrac{-11x}{{-11}} = \dfrac{-33}{{-11}}$ ${x = 3}$ Now that you know ${x = 3}$ , plug it back into $\thinspace {y = -3x+8}\thinspace$ to find $y$ ${y = -3}{(3)}{ + 8}$ $y = -9 + 8$ $y = -1$ You can also plug ${x = 3}$ into $\thinspace {-2x+3y = -9}\thinspace$ and get the same answer for $y$ : ${-2}{(3)}{ + 3y = -9}$ ${y = -1}$